// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/base/decoder_buffer_queue.h"

#include "base/logging.h"
#include "media/base/decoder_buffer.h"
#include "media/base/timestamp_constants.h"

namespace media {

DecoderBufferQueue::DecoderBufferQueue()
    : earliest_valid_timestamp_(kNoTimestamp)
    , data_size_(0)
{
}

DecoderBufferQueue::~DecoderBufferQueue() { }

void DecoderBufferQueue::Push(const scoped_refptr<DecoderBuffer>& buffer)
{
    CHECK(!buffer->end_of_stream());

    queue_.push_back(buffer);

    data_size_ += buffer->data_size();

    // TODO(scherkus): FFmpeg returns some packets with no timestamp after
    // seeking. Fix and turn this into CHECK(). See http://crbug.com/162192
    if (buffer->timestamp() == kNoTimestamp) {
        DVLOG(1) << "Buffer has no timestamp";
        return;
    }

    if (earliest_valid_timestamp_ == kNoTimestamp) {
        earliest_valid_timestamp_ = buffer->timestamp();
    }

    if (buffer->timestamp() < earliest_valid_timestamp_) {
        DVLOG(2)
            << "Out of order timestamps: "
            << buffer->timestamp().InMicroseconds()
            << " vs. "
            << earliest_valid_timestamp_.InMicroseconds();
        return;
    }

    earliest_valid_timestamp_ = buffer->timestamp();
    in_order_queue_.push_back(buffer);
}

scoped_refptr<DecoderBuffer> DecoderBufferQueue::Pop()
{
    scoped_refptr<DecoderBuffer> buffer = queue_.front();
    queue_.pop_front();

    size_t buffer_data_size = buffer->data_size();
    DCHECK_LE(buffer_data_size, data_size_);
    data_size_ -= buffer_data_size;

    if (!in_order_queue_.empty() && in_order_queue_.front().get() == buffer.get()) {
        in_order_queue_.pop_front();
    }

    return buffer;
}

void DecoderBufferQueue::Clear()
{
    queue_.clear();
    data_size_ = 0;
    in_order_queue_.clear();
    earliest_valid_timestamp_ = kNoTimestamp;
}

bool DecoderBufferQueue::IsEmpty()
{
    return queue_.empty();
}

base::TimeDelta DecoderBufferQueue::Duration()
{
    if (in_order_queue_.size() < 2)
        return base::TimeDelta();

    base::TimeDelta start = in_order_queue_.front()->timestamp();
    base::TimeDelta end = in_order_queue_.back()->timestamp();
    return end - start;
}

} // namespace media
